It has long been recognized that the injection of vapor into the carburetor of an internal combustion engine improves the efficiency and performance of the engine especially when acceleration is demanded. The liquid to be vaporized frequently is an aqueous solution of methonal alcohol.
Representative prior art patents disclosing vapor injection apparatus include U.S. Pat. No. 2,889,819 issued June 9, 1959 to A. H. Lockhead for a "Fuel Mixer for Automobile Engines," U.S. Pat. No. 3,322,105 issued May 30, 1967 to A. McIntyre for "Equipment for Augmenting the Fuel Supplied to Internal Combustion Engines" and U.S. Pat. No. 3,557,763 issued Jan. 26, 1971 to S. C. Probst for "Vapor injector."
U.S. Pat. No. 3,557,763 discloses an apparatus in which the vapor is delivered to the engine intake manifold where it is mixed with the air-fuel mixture from the carburetor inlet passage. This is a continual process. U.S. Pat. No. 3,322,105 discloses an apparatus in which the liquid to be vaporized is pulled from a tank by engine vacuum and on the way to the carburetor is mixed with air from the air cleaner. This also is a continual process. The system disclosed in U.S. Pat. No. 2,889,819 is controlled by the speed of the engine fan and is a continuous process for mixing liquid to be vaporized with air at speeds above idling speed.
It is an object of the present invention to provide an apparatus that becomes operative only at a predetermined position of the accelerator control means such as occurs when immediate acceleration is desired.